/* 
过渡元素样式命名规则
// 进入动画和离开的动作激活
transition的name值-enter-active
transition的name值-leave-active

// 进入动画和离开的动作开始
transition的name值-enter
transition的name值-leave-to
*/
.modify-enter-active,
.modify-leave-active {
  transition: opacity 2s;
}
.modify-enter,
.modify-leave-to {
  opacity: 0;
}
